The present invention relates to equipment for heating chilled or frozen foods so that they can be served.
Restaurants can now serve dishes quickly by refrigerating or freezing ready-to-eat food and heating the food when an order is received from the customer. The equipment used to heat cold foodstuffs by applying conventional technologies used for serving dishes to fit the above pattern include those shown in FIGS. 3 through 5, for example. FIG. 3 is a lateral cross section of conventional heating equipment for cold foodstuffs, FIG. 4 is a lateral cross section viewed from the direction of arrow Q in FIG. 3, and FIG. 5 is a perspective view of the placing table used in FIG. 3.
In FIGS. 3 through 5, the container 1 has a bottom 1a and sides 1b, contains heating medium 2, and is covered with a lid (not shown) as required. The placing table 21 consists of a sidewall 22 arranged above the bottom 1a of said container 1 and a support 23 on which to place foodstuffs 3 contained in rectangular parallelopiped containers arranged on top of the sidewall 22; said sidewall 22 being a rectangular parallelopiped cylinder with both ends opened, and furthermore, having throughholes 22b formed on the lower end and making contact with the bottom 1a of the container 1 to circulate the heating medium 2; said support 23 being formed in the shape shown by bending a thin metallic rod material so that foodstuffs can be placed directly on it, and consisting of a placing section 23a arranged horizontally on top of said sidewall 22, an end holding section 23b serving also as a handle formed upright on both ends of the placing section 23a, and a middle holding section 23c formed upright in the middle of said placing section 23a; and the end holding section 23b and the holding section 23c being formed parallel to each other, while the spaces between them are used to place said cold foodstuffs upright 3.
The inductive heating equipment 4 is used to heat the bottom 1a of said container 1 from beneath and consists of inverter equipment 5 that generates high-frequency currents and a coil 6 arranged apart from the container 1 to generate a high-frequency magnetic field at the center of the bottom 1a of said container 1 by receiving a high-frequency current from the inverter equipment 5.
Conventional heating equipment for cold foodstuffs has the construction as described above, wherein to heat the cold foodstuffs 3 rectangular parallelopiped foodstuffs 3 are placed upright with one its faces, the one with the smallest dimension (that is, the side in the direction of the depth) is put into contact with the spaces between the end holding section 23b and the middle holding section 23c o of said placing section 23a on the placing table 21, while water is used as the heating medium 2 and is filled into the container 1 up to a the level where the cold foodstuffs 3 are fully submerged.
The inductive heating equipment 4 is used under this condition to heat the center of the bottom 1a of the container 1. Thus, the water, which is the heating medium 2, is heated starting at the center of the bottom 1a and an upward flow 2a is generated from the center of the bottom 1a in the heated water. This upward flow 2a flows out from the openings on the top of the sidewall 22 on the placing table 21, rises through the container 1, turns to the sides 1b of the container 1 in the area on the top of the heating medium 2, and thereafter flows down along the side 1b, returning to the area near the center of the bottom 1a. That is, heating the center of the bottom 1a of the container 1 produces in the water used as the heating medium 2 a circulating flow 2b consisting of an upward flow 2a and a downward flow.
Since the cold foodstuffs 3 are placed upright with a side face in the direction of the thickness facing downward on the spaces provided on the placing table 21, said upward flow 2a flows through these spaces. Because the upward flow 2a flows through the spaces along the sides of the foodstuffs 3, these foodstuffs 3 are heated by the water 2 to a temperature that is suitable for them. The water, which is used as the heating medium 2 is generally heated to a temperature higher than 90.degree. C.
The heating equipment for cold foodstuffs that uses conventional technology heats the cold foodstuffs 3 as described above. However, because the upward flow 2a generated in the water used as the heating medium 2 flows out from the openings on the top of the sidewall 22, not all of the upward flow necessarily flows near the cold foodstuffs 3. Also, the flow that makes direct contact with the cold foodstuffs 3 in the upward flow 2a flowing near the cold foodstuffs 3 only represents a part of the flow. Therefore, the heat in the water, which is used as the heating medium 2 that is transferred to the cold foodstuffs 3 represents only a small portion of the total heat generated within the heating medium, which creates a problem in that heating the cold foodstuffs 3 takes too much time.
The present invention was intended to solve the above problems resulting from the use of conventional technologies, and is intended to provide heating equipment that can heat cold foodstuffs within a short period of time.